Concentrations of dissolved solids, a measure of the salt content in water, are elevated in many of the Nations streams as a result of human activities, according to a new USGS study. Excessive dissolved-solids concentrations in water can have adverse effects on the environment and on agricultural, domestic, municipal, and industrial water users.
Results from this study provide a nation-wide picture of where dissolved-solids concentrations are likely to be of concern, as well as the sources leading to such conditions.
“This study provides the most comprehensive national-scale assessment to date of dissolved solids in our streams,” said William Werkheiser, USGS Associate Director for Water. “For years we have known that activities, such as road de-icing, irrigation, and other activities in urban and agricultural lands increase the dissolved solids concentrations above natural levels caused by rock weathering, and now we have improved science-based information on the primary sources of dissolved-solids in the nation’s streams.”
The highest concentrations are found in streams in an area that extends from west Texas to North Dakota. Widespread occurrences of moderate concentrations are found in streams extending in an arc from eastern Texas to northern Minnesota to eastern Ohio. Low concentrations are found in many states along the Atlantic coast and in the Pacific Northwest.
The total amount of dissolved solids delivered to all of the Nation’s streams is about 270 million metric tons annually, of which about 71% comes from weathering of rocks and soil, 14% comes from application of road deicers, 10% comes from activities on agricultural lands, and 5% comes from activities on urban lands.
All water naturally contains dissolved solids as a result of weathering processes in rocks and soils. Some amount of dissolved solids is necessary for agricultural, domestic, and industrial water uses and for plant and animal growth, and many of the major ions are essential to life and provide vital nutritional functions. Elevated concentrations, however, can cause environmental and economic damages. For instance, estimated damages related to excess salinity in the Colorado River Basin exceed $330 million annually.
“This study applied statistical modeling to understand the sources and transport processes leading to dissolved-solids concentrations observed in field measurements at over 2,500 water-quality monitoring sites across the Nation,” said David Anning, USGS lead scientist for the study. “This new information was then used to estimate contributions from different dissolved-solids sources and the resulting concentrations in unmonitored streams, thereby providing a complete assessment of the Nation’s streams.”
The study determined that in about 13 percent of the Nation’s streams, concentrations of dissolved solids likely exceed 500 mg/L, which is the U.S. Environmental Protection Agency’s secondary, non-enforceable drinking water standard. Many of these streams are found in a north-south oriented band stretching from west Texas to North Dakota.
While this standard provides a benchmark for evaluating predicted concentrations in the context of drinking-water supplies, it should be noted that it only applies to drinking water actually served to customers by water utilities.
An online, interactive decision support system provides easy access to the national-scale model describing how streams receive and transport dissolved solids from human sources and weathering of geologic materials. The decision support system can used to evaluate combinations of reduction scenarios that target one or multiple sources and see the change in the amount of dissolved solids transported downstream waters.
The dissolved-solids model was developed by the USGS National Water-Quality Assessment Program, which provides information about water-quality conditions and how natural features and human activities affect those conditions. Information on modeling applications, data, and documentation can be accessed online.
JACKSON, Miss. – Federal assistance approved for disaster survivors in 12 Mississippi counties has reached almost $16.5 million.
Here is a summary through Thursday, June 12, of all federal assistance to individuals and households in the 12 counties designated for FEMA Individual Assistance. The severe storms, tornadoes and flooding occurred from April 28 through May 3, 2014.Language English
Little Rock, Ark. – To meet the needs of Arkansans affected by the April 27 severe storms, tornadoes and flooding, the state/federal Disaster Recovery Center in Mayflower will transition into a U.S. Small Business Administration (SBA) Disaster Loan Outreach Center on Monday, June 16.
The center’s hours will be 9 a.m. to 6 p.m. Monday through Friday. The center will close Thursday, June 26, at 6 p.m.
Little Rock, Ark. – Survivors of the April 27 severe storms, tornadoes and floods have until 2 p.m. Saturday, June 14, to visit the Disaster Recovery Centers in Mayflower and Vilonia.
The state and FEMA have closely monitored visitor traffic at the centers in Arkansas. Traffic to these centers has significantly decreased, indicating the information needs of survivors in the area have been met.Language English
Little Rock, Ark. – Effective June 9, 2014, the State/FEMA Disaster Recovery Centers (DRC) in Mayflower and Vilonia will be open from 9 a.m. to 6 p.m. Monday–Friday. The DRCs are also open from 9 a.m. to 2 p.m. on Saturdays.
Survivors of the severe storms, tornadoes and floods have until June 14 to visit one of the Disaster Recovery Centers.Language English
Little Rock, Ark. – Effective immediately, the State/FEMA Disaster Recovery Centers (DRC) in Vilonia and Mayflower will have new Saturday hours.
The centers will be open 9 a.m. to 2 p.m. Saturdays. The centers will continue to be open from 9 a.m. to 7 p.m. Monday–Friday.
Disaster Recovery Center Locations:Language English
LITTLE ROCK, Ark. – Residents of Faulkner, Pulaski, Randolph and White counties who suffered damages as a result of the flooding, severe storms and tornadoes of April 27 have until June 30 to register for state/federal Individual Assistance.Language English
FEMA mitigation teams will be at home improvement stores in Conway and Little Rock to offer information and answer questions. The experts can provide advice on rebuilding after a disaster, offer tips to build hazard-resistant homes and provide information on building a safe room in your home.Language English
LITTLE ROCK, Ark. – Survivors of the April 27 severe storms, tornadoes and floods may be eligible for Disaster Unemployment Assistance (DUA). Disaster Unemployment Assistance provides unemployment benefits and re-employment services to people who have become unemployed because of the storms.
Residents of Faulkner County have until June 2 to apply for DUA.
The DUA deadline for residents of Pulaski, Randolph and White counties is June 5.Language English
Following is a summary of key federal disaster aid programs that can be made available as needed and warranted under President Obama's disaster declaration issued for the State of Vermont.
Assistance for the State and Affected Local Governments Can Include as Required:Language English
WASHINGTON, D.C. – The U.S. Department of Homeland Security's Federal Emergency Management Agency announced that federal disaster aid has been made available to the State of Vermont to supplement state and local recovery efforts in the area affected by severe storms and flooding during the period of April 15-18, 2014.Language English
A visit to hurricane-battered Louisiana inspired prompt digital planning after the SR 530 Slide that will sustain communications needs for the long haul.Language English
Montgomery, Ala. – Severe weather can happen any time of the year. The best way to prepare for it is with a family emergency plan. If you don’t have one, develop one. If you have an emergency plan, review and update it, then go over it with your family at least once a year.Language English
PENSACOLA, Fla. – The State/FEMA disaster recovery center located at the Gulf Breeze Recreation Center is transitioning Wednesday, June 11, to a U.S. Small Business Administration disaster loan outreach center.
SBA customer service representatives will be on hand at the loan outreach center to answer questions about SBA’s disaster loan program and explain the application process. Survivors can get help applying for or closing low-interest disaster loans. The center is located at:
Gulf Breeze Recreation CenterLanguage English
PENSACOLA, Fla. – Residents of Escambia and Santa Rosa counties who were unemployed as a result of the April 28 to May 6, 2014, severe storms and flooding, have until Monday, June 9, to apply for federal Disaster Unemployment Assistance benefits.
Residents of Okaloosa and Walton counties have until Thursday, June 12, to apply, and Jackson County residents have until Monday, June 23, to apply.Language English
PENSACOLA, Fla. – One month after severe storms, tornadoes and flooding hit parts of the Florida Panhandle, almost $50 million in state and federal disaster assistance has been approved as survivors continue to rebuild their homes, businesses and communities.Language English